Hospital bed



Patented July 13, 1948 UNITED STATES PATeNTMoFFIoE',

Marvel D. Beem, West Los Angeles, Calif., assignor of one-half to The Beem Foundation, Los Angeles, Calif., a charitable trust of California Application October 15, 1945, Serial No.1622,38-7` This invention relates to hospitalv beds. It deals particularly with the lift mechanism of a hospital'bed, and has as its general object to prol vide a hospital bed in which the same lift mech-J anism is employed alternatively for lifting the hinged sections of the bed to seat forming positions,'or for longitudinally tilting the entire' mattress supporting frame of the bed either to a Trendelenburg position or a reverse 'lrenf-V delenburg position. v

Another object of the invention is to 'provide a hospital bed, which in addition to mechanism for producing the Trendelenburg andthe "reverse Trendelenburg positions, is adapted'to continuously oscillate the lmattress frame between the Trendelenburg and reverseTrendelenburg positions for cardio-therapy treatments.

In general, these objects are attained by at taching the hinged mattress supporting frame sections to a rigid subframe which is free to be elevated; by applying the lifting forcedirectly to the hinged sections so that normal operation of the elevating mechanism will'cause only the hinged section to raise; and by providing means for locking the hinged sections to the subframe so that the lifting force applied to the hinged sections will be transmitted to the subframe, whereby the entire mattress supporting frame may be lifted as a rigid unit.

The mattress supporting frame sections yare hinged, in a generally conventional manner, to`- the subframe with the head rest and thigh sec-` tion hinged to each other and to the subframe and with the foot rest hinged to the thigh section to form a knee joint. Lifting pressure is applied to the head rest and to the thigh section near the knee joint. One of the' problems thatj I have encountered in the development of theinvention is the-possibility of the entire 'mat- `v tress supporting frame tilting about the axis ofv contact of the lifting means with the thigh s'ec-4 tion in the event that downward pressure is applied to the foot end of the frame. To prevent such tilting, the invention provides means whereby the head end of the frame may be restrained' against moving upwardly whenever the thigh section is being elevated. However, a further problem has been encountered in connection with 11 Claims. (c1. ylia- 33) y' mentioned 'features and yet relatively simple and inexpensive in construction.

Another `object is -to provide an automatic control for the oscillating feature. d

'Other vobjects of the-invention will appear from aperusal of the following specification, in cony nection with the appended drawing, in which:

Fig. 1 is a longitudinal Asectional view through a hospital bed-embodying the invention; l

Figf2'is 'a transverse sectional view of the same taken on` the line 2-2 of Fig. l;

Fig. 3 is a detailed transverse sectional'view taken on the line 3-3 of Fig. 1;

Fig. '4 is -a transverse sectional view of the bed, taken on theline4-4 of Fig. 1; and' v `ig.f5` is a plan view of one of,4 the elevator units, n, y j

As an example of'one form' in which the invention may be embodied, I have shown in the drawingsahospital bed embodying a head panel |0,fa foot panel ||,l longitudinal rails I2 connected'tofthe ,head :and foot panels I0 kand ,to

form a rigid bed frame structure, and amattres's supporting frame |3 carried by the rails I2, together withelevating mechanism which is indicated generally at |4. y

The mattress supporting frame |13 includes a subframe I5 .which embodies longitudinal rail members I8 connected attheir ends by transverse barst-I9 and transverse channels |911. Secured in the channels .I 9a, at theends thereof, are Vsupporting elements I6 whichnormally rest in channels-.Il butmay lift out of the channels to permit the mattress supporting frame I3 to be `elevated tothe Trendelenburgpositions 're-,-

ferred to hereinafter.'

The mattress supporting frame I3 also includes three hinged sections 20,- 2| and 22, of which the section 20;,(head restiand the section 2| (thigh section) are hinged to each other and to the subframe I8 through hinge mechanism 23. The

footrest :22 is hinged' to the thigh section 2| by hinge mechanism 24. The free ends of the head rest 20 andv foot rest -22 are adapted to rest against the transverse 'members I9 when inv their lowered,l aligned positions.

Theelevating mechanism for the head rest 20 includes a'pair of arms `25fhingedat 26 to the inner side of the rails` |8f and lhaving at their oppositeends `rol-1ers Z'lwhich engage L-section rails 28 that are secured to the head rest 2|).` Elevating power is derived from a' motor M which is pivoted at 29 to a bracket 30 attached to the head Ipanel lll;v Such power is transmitted through reduction gearingA 3| to an internally threadedy sleeve 3-2' that coacts with a threadedshaft 33'threa'ded thereinto. The threaded shaft 33 forms part of' apushrro-d 34 which is pivotedl at '35 to a' lever 36.' i'I'he' lever 361s secured to a? 3 shaft 31 which carries a pair of arms 38 that are linked to the arms I25 through links '39.

Similar mechanism, including" a motor M', reduction gearing 3 I', an internally threadedsleeve 32', a threaded shaft 33', a push rod 34', an arm 36', :a shaft 31', a pair of arms 38', and a pair of links 39', functions to transmit lift through a pair of arms 25' and rollers 21' to the thigh section 2| through L-section rails 28'` secured to the thigh section 2|. Arms 25 are h-inged'at 26' to the rails I8.

The head rest 20 may be locked to thel subframe I8 by a pair of latches 40 which are carried by a shaft 4| journalled in the rails I8; The latches 40 coact with hooks 42 which are secured (as by welding) to the inner side faces of the side members of the foot rest 22. One end of the rod 4|l projects beyond the outer sideof the foot rest 22 and has secured thereto a handle 43 by means of which the shaft 4|, and with it the latches 40, may be rotated so as to move the latches into and out of engagement with the hooks 4 2.

An identical latching arrangement, similar parts of which are indicated by corresponding reference numerals 40. etc., is used for latching the foot rest 22, adjacent the knee hinge 24, 'toA the subframe |8.

With the latches 49' engaged with the hooks 42', elevating movement applied to the thigh section 2| through the rollers 21 will raise the foot end of the mattress supporting frame while the head end of the frame. remains lowered. This position is indicated at T, and is known as the Trendelenburg position.

With the latches 4 0 engaged with the hooks 42, elevating movement applied to the head rest through the rollers 21 will raise the head portionr of the mattress supporting frame while the foot portion remains in engagement with the subframse i9. This position, indicated in broken lines at RT, is known as the reverse Trenelenburg position.

When the mattress supporting frame is being raised to the` Trendelenburg position, the head end thereof is restrained against elevating move` ment which might occur as the result'of applicationof Weight to the foot end of the mattress frame, causing the frame to teeter about the axis cf the rollers 21` To avoid this occurrence, I provide an interlock mechanism including a pair of hooks 46 which are pivoted at 41` to the xed frame rails l2 and which are connected by operating rods 48 and extension springs 49, to the arms 36 of the thigh section elevating mechanism. Through thisA mechanism, the initial elevating movement of the thigh section raising mechanism will cause the hooks 46 to be projected into engagement with keepers 50 attached to a transverse member 9 of the subframe l5, and additional movement of the arm 36' will be permitted by the stretching, of the coil springs 49, which exert only light tension between the arms 36 and the hooks 46. The engagement of the hooks 46 with the keepers 59 effectively pre-- vents elevation of the head end of the subframe I8.

The motors M and M'v are energized from a suitable source of current through current supply conductors 52, 52'. The motors M, M' are` reversible motors and their respective forward and reverse coils are connected to conductors 53, 53' and; 5,4, 54' through the contacts 55, 55, and 56,756' of two-way switches 51,A 51" through which therespective coils may be connected@V to:` ground rotatablecommutator brush 66, driven by a motor 6|, and` connected to ground by a suitable connection 62. The motor l6I is connected to current supply by suitable conductor 63, and is under the control of a manual switch 64, grounded through a conductor 65.

` As the brush 6l)A rotates, it consecutively engages a plurality of contacts 66, 61, 68 and 69, which are connected respectively -to the conductors 53, 54, 53' and 54', thus consecutively making and breaking the circuits for elevating and lowering the head rest and for elevating and lowering the knee joint. The contacts 66-69 are of sufficient length circumferentiallyof the path :fof revolution of the brush 66, so that the durationV of contact of the brush with eachfcontact will be adequate to permit the desired amount of ele-` vation. and lowering of the mattress supporting frame. The upper and lower limits oi' said elevation and lowering will, however, be overcontrolled by limit switches 10, 1|, 19' and 1| in the Y ity and clarity, it' being understood that the limit switches may and preferably should be positioned to be directly engaged by the mattress supporting sections 29, and 2| or 22.

I claim as myfinvention:

1.' In a hospital bed, a mattress supporting frame including .a subframe; a head rest and a thigh section hinged to said'subframe, and a foot rest hinged to said thigh section to provide a knee joint; lift mechanism operative to exert lifting pressure against said head rest and knee joint respectively; and means for locking said head rest and knee joint to said subframe to permit said mattress supporting frame to be elevated as a rigid unit.

2. In a hospital bed, in combination with a main supporting structure; a mattress supportingframe including a subframe, a head rest and thigh section hinged to said subframe, and a foot rest hinged to said thigh section to form a knee joint; lift mechanism operatively connected be tween said main supporting structure and said head rest and knee joint respectively and adapted to exert lifting pressure against said head rest and knee joint respectively; whereby to elevate said head rest and knee joint respectively without moving said subframe; and means for locking said head rest and knee joint to said subfrarne to permit the lift of said lifting mechanism to elevate said mattress supporting frame as a rigid unit. l

3. In a hospital bed, in combination with a main supporting structure; a mattress supporting frame including a sub-frame, a head rest and thigh section hinged to lsaid sub-frame, and a foot rest hinged to said,v thigh section to form a knee joint; lift mechanism operatively connected between said main supporting structure and said head. rest and knee joint respectively and adapt- 4edto exert lifting pressure against said head rest and knee joint respectively, whereby to elevate said head rest and knee joint respectively without moving said subframe; and means for selectively locking either said head rest or said knee joint to said subframe to permit either end of said mattress supporting frame to be elevated as a rigid unit.

4. In la hospital bed in combination with a fixed frame structure; a mattress supporting frame including a subframe, a head rest and thigh section hinged to said subframe, and a foot rest hinged to said thigh section to form a knee joint; lift mechanism operatively connected between said fixed frame structure and said head rest and adapted to exert lifting pressure against said head rest so as to normally elevate the same without moving said subframe; and means for locking said head rest to said subframe to permit said lift mechanism to elevate said mattress supporting frame as a unit to a reverse Trendelenburg position.

5. In a hospital bed, in -combination with a fixed frame structure; a mattress supporting frame including a subframe, a head rest and thigh section hinged to said subframe, and a foot rest hinged to said thick section to form a knee joint; llift mechanism operatively connected between said fixed frame structure and said knee joint to exert lifting pressure against said knee joint so as to normaily elevate the same normally without moving said subframe; and means for locking said knee to said subframe to permit said lift mechanism to elevate said mattress supporting frame including said subframe as a unit to a Trendelenburg position.

6. In a hospital bed, in combination with a xed frame structure; a mattress supporting frame including a subframe, a head rest and thigh section hinged to said subframe and a foot rest hinged to said thigh section to form a knee joint; lift mechanism operatively connected between said xed frame structure and said head rest and knee joint respectively and adapted to exert lifting pressure against said head rest and knee joint respectively for normally elevating said head rest and knee joint respectively without moving said subframe; means for locking said head rest and knee joint to said subframe to permit said lift mechanism to elevate said mattress supporting frame including said subframe as a rigid unit; and control means for effecting the consecutive alternate operation of said head rest and knee joint lift mechanism in a manner to raise and lower the head and foot ends of said mattress supporting frame in alternating succession.

'7. In a hospital bed, in combination with a fixed frame structure, a mattress supporting frame normally supported by said iixed frame structure in a horizontal position, lift mechanism for elevating the head end of said mattress supporting frame while the foot end thereof remains fulcrumed against said fixed frame structure, lift mechanism for elevating the foot end of said mattress supporting frame while the head end thereof remains fulcrumed against said fixed frame structure, and control means for operating said lift mechanisms in alternating succession.

8. In a hospital bed, in combination with a fixed supporting frame structure, a mattress supporting frame normally supported on said fixed frame in a horizontal position; and lift mechanism for raising and lowering the head and foot ends of said mattress supporting frame in alternating succession, with one end of said mattress supporting frame remaining fulcrumed against said fixed frame structure while the other end is being raised and lowered.

9. In a hospital bed, in combination with a iixed frame structure; a mattress supporting frame including a subframe, a head rest and thigh section hinged to said subira-me, and a foot rest hinged to said thigh section to form a knee joint; lift mechanism operatively connected between said fixed frame structure and said head rest and knee joint respectively and adapted to exert lifting pressure against said head rest and knee joint respectively whereby to normally elevate said head rest and knee joint respectively without moving said subframe; means for locking said head rest and knee joint to said subframe to permit said lift mechanism to elevate said mattress supporting frame as a rigid unit; and means automatically operated in synchronism with said lift mechanism, and adapted to restrain elevation of one end of said mattress supporting frame while the other end is being elevated.

10. In a hospital bed, in combination with a fixed supporting frame structure, a mattress supporting frame normally supported on said fixed frame structure in a horizontal position; lift mechanism operatively connected between said iixed frame structure and a region of said mattress supporting frame intermediate the ends thereof and adapted to exert lifting pressure thereagainst for elevating one end thereof; and means automatically operated in synchronism with the operation of said lift mechanism for restraining operation of said other end of said rmattress supporting frame while said one end is being elevated.

11. In a hospital bed, -in combination with a xed supporting frame structure, a mattress supporting frame normally supported on said xed frame structure in a horizontal position; lift mechanism operatively connected between said xed frame structure and a region of said mattress supporting frame intermediate the ends thereof and adapted to exert lifting pressure thereagainst for elevating one end thereof; and means for restraining operation of said other end of said mattress supporting frame while said one end is being elevated.

MARVEL D. BEEM.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,110,920 Gibson et al Sept. 15, 1914 2,104,745 Howell et al Jan. 11, 1938 2,303,433 Caldwell et al Dec. 1, 1942 

